1. Field of the Invention
The present invention relates to a urethaneresin coated electrical wire. More particularly, the present invention relates to an electrical wire with a urethane resin coating layer that can be easily applied by extrusion coating and which provides for great ease in the circuit wiring with such a wire.
2. Background Art
Urethane resins have superior properties such as high mechanical strength, wear resistance and flexibility, and hence are extensively used as coating materials for various kinds of lead wires. However, urethane resins display elastomeric properties even when they are being extruded, so if they are used as coating materials for a multi-conductor electric wire composed of a stranded core of two or more twisted insulated conductors, the pressure exerted by the resin being extruded will cause the insulation coat on each conductor to deform. The tendency of the insulation coat to deform is particularly great at the interface between two adjacent turns of a conductor. If the extrusion conditions are extreme, the twisted conductors may be short-circuited as a result of deformation of the insulation coating.
In addition, urethane resins which have high mechanical strength and adhere strongly to other resins are very difficult to strip in the operations of the end-use preparation of the wire. The conventional method of stripping the jacket of urethane resin by cutting with a hot wire is cumbersome and a need exists for using a jacket system that is highly amenable to operations associated with its final preparation.